Investigation of experience-dependent post transcriptional regulation of Drosophi

果蝇经验依赖性转录后调控的研究

基本信息

批准号：
8761101
负责人：
Kausik Si
金额：
$ 41.25万
依托单位：
STOWERS INSTITUTE FOR MEDICAL RESEARCH
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-08-01 至 2019-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8761101
关键词：
Address Adult Affect Amino Acid Substitution Antigens Aplysia Behavioral Brain Code Cognitive deficits Conditioned Stimulus Cues Development Drosophila genus Drosophila melanogaster Episodic memory Excision Exposure to Family Family member Food Functional disorder Genes Head Homologous Gene Hour Human Immunoprecipitation Introns Investigation Learning Length Link Mediating Memory Messenger RNA Molecular Motor Mus Mutation Neurons Odors Organism Play Post-Transcriptional Regulation Process Production Protein Biosynthesis Protein Isoforms Proteins RNA Splicing RNA-Binding Proteins Reporter Role Sensory Serotonin Short-Term Memory Starvation Stimulus Sucrose Synapses Synaptic plasticity Syndrome System Terminator Codon Training Transcript Transcription Initiation Site Translating addiction antigen binding base crosslink experience fly in vivo insight long term memory memory process mutant overexpression protein expression public health relevance response stem

项目摘要

DESCRIPTION (provided by applicant): Although a large number of experiences produce transient memory only some of them form stable long-term memory. The value of the experience and internal state of the organism plays an important role in determining this transition from short-term to long-term memory. However, how external experience and the internal state of the organism interact at a molecular level to influence memory storage is largely unknown. The synthesis of new proteins is required to form stable long-term memory. CPEB, a family of RNA-binding proteins, regulate activity-dependent protein synthesis in the neuron. In Aplysia, a specific CPEB family member, ApCPEB, is required for the persistence of activity-dependent increase in synaptic strength beyond 24 hours. In Drosophila, a CPEB family member Orb2 is required to stabilize memory beyond 12 hours. In mice and human a CPEB family member CPEB3 has been linked to episodic memory formation. These observations suggest that CPEB family members play evolutionarily conserved role in the persistence of memory. The Drosophila Orb2 gene produces two distinct primary transcripts from two different transcription start sites, encoding the Orb2A and Orb2B proteins. Mutations that selectively inactivate Orb2A protein specifically destabilize long-term memory. We have found that the Orb2A mRNA has two forms; an intron containing unspliced form that does not code for Orb2A protein (Orb2A-np) and a spliced form that codes for full length Orb2A protein (Orb2A-pc). Surprisingly, the Orb2A-np mRNA is the prevalent isoform in the adult brain and exposure to cues that form associative long-term memory in flies, such as exposure of hungry flies to sucrose and odor increases the level of protein coding spliced Orb2A-pc transcript. The Drosophila orthologue of mammalian splicing regulator Nova binds Orb2A transcript and regulates the formation of Orb2A-pc mRNA. In this proposal we intend to dissect the behavioral cues and Nova-dependent molecular mechanism that regulate the level of protein coding Orb2A transcript. We also intend to address when and how long Orb2 proteins are required for persistence of memory. We hope that an understanding of the interaction of experiences and molecules that stabilize memory would be useful to understand addictions and post traumatic syndromes, in which a single experience forms extremely stable memory. Also, we hope to gain insight into the role of regulated mRNA processing in long-lasting memory.

描述（由申请人提供）：尽管大量经验会产生瞬态记忆，其中一些经验形成了稳定的长期记忆。生物体的体验和内部状态的价值在确定从短期到长期记忆的过渡中起着重要作用。但是，外部经验和生物体的内部状态如何在分子水平上相互作用以影响记忆存储未知。需要新蛋白的合成才能形成稳定的长期记忆。 CPEB是一种RNA结合蛋白家族，调节神经元中的活性依赖性蛋白质合成。在Aplysia中，特定的CPEB家族成员APCPEB是依赖活动依赖性突触强度增加24小时的持续性所必需的。在果蝇中，需要CPEB家庭成员ORB2才能稳定超过12小时的记忆。在小鼠和人类中，CPEB家族成员CPEB3与情节记忆形成有关。这些观察结果表明，CPEB家庭成员在记忆的持久性中扮演着进化保守的作用。果蝇ORB2基因从两个不同的转录起始位点产生两个不同的主要转录本，编码ORB2A和ORB2B蛋白。有选择性地使ORB2A蛋白特异性不稳定长期记忆的突变。我们发现ORB2A mRNA有两种形式。包含不绘制的形式的内含子，该内含子不为ORB2A蛋白（ORB2A-NP）编码，并编码为全长ORB2A蛋白（ORB2A-PC）的剪接形式。令人惊讶的是，ORB2A-NP mRNA是成年大脑中普遍的同工型，并暴露于形成果蝇中缔合性长期记忆的提示，例如暴露于饥饿的果蝇中，可能会增加蔗糖和气味，这会增加蛋白质编码的蛋白质编码水平。哺乳动物剪接调节剂NOVA的果蝇直系同源物结合ORB2A转录本，并调节ORB2A-PC mRNA的形成。在此提案中，我们打算剖析调节蛋白质编码ORB2A转录水平的行为提示和NOVA依赖性分子机制。我们还打算解决ORB2蛋白何时以及需要多长时间才能持久记忆。我们希望对稳定记忆的经验和分子的相互作用的理解对于了解成瘾和创伤后综合症将很有用，在这种情况下，单个体验形成非常稳定的记忆。另外，我们希望深入了解受调节的mRNA处理在持久记忆中的作用。